My dad died and left a will which my step family have not let me see.they said that it was out of date and when my dad got cremated I was not allowed to know who the funeral director was or is who has his ashes. So I would like to know who has legal rights over his ashes please.

Your general location is important to receive the best possible answers.

You need to get an attorney and force probate of the will as well as put in a claim for the ashes. Most likely his legal spouse has precedence.

Where you live, and also what you mean by 'out of date.' A will doesn't go out of date unless a new one is written.

I assume "my step family" means your father's widow, her children from a previous relationship &/or your half siblings (her children by your father). Is this assumption correct?

Get an attorney who will demand that the will be produced. If they refuse, the probate court will order them to comply.